This invention relates to a gas heat pump air conditioner and more particularly to an improved powering internal combustion engine and crankcase ventilating system for such an engine.
As is well known, internal combustion engines are employed for providing, power in a variety of applications. One proposed application for internal combustion engines is to employ them as a powering source for driving a compressor of a gas heat pump. In such applications, the internal combustion engine itself is powered by a gaseous fuel. Internal combustion engines have great utility in such applications because of their efficiency.
However in an application of this type for internal combustion engines, the engine may be called upon to run for long periods of time without servicing. When this is done, it is extremely important to insure that the crankcase and lubricating system for the engine is adequately ventilated, that contaminates are removed from the lubricating oil and that in doing so the oil itself does not become further contaminated.
That is, it is well known to provide a system wherein there is a flow of ventilating gas through the crankcase and lubricating system of the engine. Such ventilating systems have been found to substantially reduce the deterioration of the lubricant. However, for emission control it is desirable to insure that the crankcase ventilating gases are not discharged directly to the atmosphere. The reason for this is that they may contain a fairly high percentage of unwanted constituents, such as hydrocarbons resulting from blowby during engine operation.
It has, therefore, been the practice to return the crankcase ventilating gases to the engine induction system so that any unburned hydrocarbons can be further oxidized and consumed in the combustion chamber without being discharged directly to the atmosphere.
FIG. 1 is a cross sectional view of a conventional type of prior art internal combustion engine having a conventional type of crankcase lubricating system of the type aforedescribed. In this figure, the conventional engine is identified generally by the reference numeral 21 and is shown in a cross sectional view taken through its single cylinder. The engine 21 includes a cylinder block 22 in which a cylinder bore 23 is formed. A piston 24 reciprocates in this cylinder bore 23 and is connected by means of a piston pin 25 to the upper or small end of a connecting rod 26.
The connecting rod 26 has its lower or big end 27 journaled on a throw 28 of a crankshaft that is rotatably journaled within a crankcase chamber 29. The crankcase chamber 29 is formed by a skirt 31 of the cylinder block 22 and a oil pan 32 that is affixed to the skirt 31 in any suitable manner. A lubricant, such as oil is contained at a level shown by the dot/dash line 33 in the oil pan 32 for lubrication of the engine 21 through any suitable and well known type of lubricating system.
A cylinder head assembly, indicated generally by the reference numeral 34 is affixed to the cylinder block 22 in a known manner and has a lower recess 35 which defines, in part, the combustion chamber of the engine 21 along with the head of the piston 24 and cylinder bore 23. An intake charge is delivered to the combustion chamber 35 through an intake port 36 having an intake valve (not shown) that controls the communication of the intake port 36 with the combustion chamber 35. In a like manner, an exhaust passage 37 connects the combustion chamber 35 with the atmosphere through an exhaust system (not shown). An exhaust valve (not shown) controls the communication of the combustion chamber 35 with the exhaust passage 37. The intake and exhaust valves and their operating system have not been shown because they are well known in the art and the descriptive matter relates to the crankcase ventilation system, which is the area where the invention resides.
An air charge for the intake passage 36 is drawn from the atmosphere through an air inlet device, indicated generally by the reference numeral 38 which has an inlet opening 39. The air inlet device 38 has a discharge opening 41 with a filter element 42 being disposed between the inlet opening 39 and the outlet opening 41 for filtering the atmospheric air that is drawn for the induction system. A manifold and induction system 43 connects the air inlet device outlet 41 with the intake passage 36 of the cylinder head. A throttle valve assembly 44 is provided in the induction system 43 for controlling the speed of the engine 21 in a well known manner. A source of gaseous fuel is supplied to the engine at an appropriate position in the induction system 43.
As has been noted, it is desirable to provide a source of ventilating air for the lubricating system and particularly so as to ventilate the crankcase chamber 29. These ventilating gases in the conventional prior art type of construction are derived from the atmosphere but are generated by the blowby gases flowing past the piston 24 in the manner as shown by the dot/dash arrows in the figure. These gases then pass across the upper surface of the lubricant 33 and through an internal separator 45 formed in the skirt portion 31 of the cylinder block 22 so as to entrap larger lubricant particles and cause them to be delivered back to the crankcase chamber 29. These lubricating gases that had a coarse separation accomplished then pass through a vertically extending passage 46 formed at one side of the cylinder bore 23 and exit through a discharge fitting 47.
A flexible conduit 48 connects this discharge fitting 47 with the air intake device 38 downstream of the filter element 42. A further filter element 49 is provided in the air inlet device 38 for filtering the crankcase ventilating gases before they pass through the air inlet device outlet 41 for flow back into the engine through the induction system 43. The separator 49 will tend to remove larger particles of liquid such as lubricant and/or water vapor. As is well known, water vapor is generated by the combustion process in the engine and hence there will be a fairly large amount of water vapor in the crankcase ventilation gases.
Since the filter 49 is provided in the air inlet device 38, the air inlet device 38 and filter element 49 will operate at a considerably lower temperature than the temperature of the ventilating gases. As a result, water vapor tends to condense out into the filter element 49 and can flow back through the conduit 48 to the crankcase chamber 33 to cause dilution of the lubricant therein and other problems. In addition, there is the problem that condensation can actually form directly in the filter element 49 and may clog the filter element 49. Hence, the prior art constructions as described have these disadvantages each of which will reduce the quality of the lubricant in the crankcase chamber during long periods between servicing.
It is, therefore, a principal object of this invention to provide an improved lubricating and crankcase ventilating system for an internal combustion engine.
It is a further object of this invention to provide an improved crankcase ventilating system for an internal combustion engine that will provide extremely long service intervals for changing of the lubricant in the engine.
It is a further object of this invention to provide an improved lubricating and crankcase ventilating system for an internal combustion engine wherein water vapor can be easily extracted from the lubricant and the gases that flow through the crankcase chamber while oil will be condensed and reconveyed to the crankcase chamber.
It is a yet further object of this invention to provide an improved crankcase ventilating system for the gas powered internal combustion engine of a heat pump.